KR101452734B1

KR101452734B1 - Drawing press controlling blank holding force with MR damper

Info

Publication number: KR101452734B1
Application number: KR1020140063610A
Authority: KR
Inventors: 윤동식
Original assignee: (주)메카스
Priority date: 2014-05-27
Filing date: 2014-05-27
Publication date: 2014-10-22

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing press for controlling a blank holding force using an EM damper. More specifically, the MR damper is applied to the blank holder of the drawing press to adjust the magnitude of the current applied to the coil, thereby changing the intensity of the magnetic field induced in the coil, thereby adjusting the viscosity of the MR fluid to vary the spring force (BHF) can be adjusted without additional equipment in the mold, even if the molding conditions change, such as changing the material of the material panel, changing the cushion pressure of the drawing press, changing the shape of the product, By applying the MR damper instead of the hydraulic cylinder method which requires the piping work or the hydraulic piping and the hydraulic supply system, Drawing that controls the blank holding force using a damper Lt; / RTI >
To this end, the present invention relates to a first type, mounted on a bolster, having a space corresponding to the shape of a lower surface of a product to be processed, and supporting a panel to be processed into a product; A second mold mounted on the slide and having a protrusion corresponding to the shape of the top surface of the product to be machined, the mold being arranged to face the first mold; And a blank holder mounted on the slide, the blank holder being spaced apart from the second die so as to press the panel contacting the upper surface of the first mold, wherein the blank holding force is controlled using an emblem damper.

Description

[0001] Drawing press controlling blank holding force using MR damper [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing press for controlling a blank holding force using an EM damper. More specifically, the MR damper is applied to the blank holder of the drawing press to adjust the magnitude of the magnetic field applied to the coil by adjusting the magnitude of the current applied to the coil, thereby adjusting the viscosity of the MR fluid to vary the spring force (BHF) can be adjusted without additional equipment in the mold, even if the molding conditions change, such as changing the material of the material panel, changing the cushion pressure of the drawing press, changing the shape of the product, By applying the MR damper instead of the hydraulic cylinder method which requires the piping work or the hydraulic piping and the hydraulic supply system, Drawing that controls the blank holding force using a damper Lt; / RTI >

Deep Drawing is a method of reducing the diameter of a material or narrowing the periphery of a sheet to a center and processing it into a crucible. A drawing press is used for deep drawing processing.

The force for fixing the space between the die and the blank holder in the drawing press is called a blank holding force (BHF). BHF is one of the important factors to be controlled in sheet metal processing.

For example, when BHF is insufficient, wrinkles occur in the sheet metal, and when the BHF is excessive, the sheet metal may be torn.

Gas-spring type and hydraulic cylinder type are generally used to control BHF.

1 is a conceptual diagram of a general gas spring method.

In FIG. 1, the left side corresponds to a gas spring without an accumulator, and the right side corresponds to a gas spring with an accumulator.

In the gas spring type, gas injected into the cylinder serves as a working medium.

The gas spring method has the advantages of relatively low cost, easy installation, and insertion into various presses. However, the gas spring method has a problem in that it exhibits a forward force behavior of the force with respect to the stroke. In the deep drawing, reverse BHF is often required. However, according to the gas spring method, there is a problem that it can not be coped with in such a case.

The hydraulic cylinder method has the advantage of high control accuracy, but it has a high cost and a very complicated structure.

Prior Art Document: KR Registration Practical Utility Model No. 0383794 (published on May 5, 2005)

It is an object of the present invention to provide a drawing press capable of overcoming the problems of a gas spring type and a hydraulic cylinder type and varying the spring force of the blank holder in a simple process and at a low cost, There is a purpose.

To achieve the above object, a drawing press for controlling a blank holding force using an emblem according to the present invention is mounted on a bolster and has a space corresponding to a shape of a lower surface of a product to be processed A first mold supporting a panel to be processed into a product; A second mold mounted on the slide and having a protrusion corresponding to the shape of the top surface of the product to be machined, the mold being arranged to face the first mold; And a blank holder mounted on the slide, the blank being spaced apart from the second mold to press the panel contacting the upper surface of the first mold.

The blank holder includes a cylinder accommodating an MR fluid (Magneto-Rheological Fluid) therein, an outer piston inserted into the cylinder, an inner piston provided inside the outer piston, a coil provided between the outer piston and the inner piston, And a piston rod whose end is engaged with the outer piston and the inner piston.

Further, the present invention may further include a current regulator which is electrically connected to the coil to induce a magnetic field in the coil by applying a current to the coil, and adjusts the intensity of the magnetic field through the intensity of the current.

According to the present invention, by applying the MR damper to the blank holder of the drawing press to adjust the magnitude of the current applied to the coil, the intensity of the magnetic field induced in the coil can be changed, thereby adjusting the viscosity of the MR fluid, There is an effect.

Further, according to the present invention, it is possible to adjust the blank holding force (BHF) without additional devices in the mold even if the molding conditions such as the material change of the material panel, the cushion pressure change of the drawing press, There is a possible effect.

Further, according to the present invention, by applying the MR damper instead of the gas cylinder method in which the gas piping operation is required, or the hydraulic cylinder method in which the hydraulic piping and the hydraulic pressure supply device must be installed, the blank holding force of the drawing press can be adjusted by power supply alone, And low cost can be realized.

1 is a conceptual view of a general gas spring system,
FIG. 2 is a conceptual diagram of a drawing press for controlling a blank holding force using an MMP damper according to a preferred embodiment of the present invention,
FIG. 3 is a partially cutaway perspective view showing the internal structure of the blank holder in FIG. 2,
Fig. 4 is an enlarged perspective view of the coil portion in Fig. 3;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, the preferred embodiments of the present invention will be described below, but it is needless to say that the technical idea of the present invention is not limited thereto and can be variously modified by those skilled in the art.

FIG. 2 is a conceptual diagram of a drawing press for controlling a blank holding force using an emblem according to a preferred embodiment of the present invention, FIG. 3 is a partially cutaway perspective view showing the internal structure of the blank holder of FIG. 2, 3 is an enlarged perspective view of the coil portion.

A drawing press for controlling a blank holding force (BHF) using an MR damper according to a preferred embodiment of the present invention includes a bolster 10, a first mold 12, a slide 20, 2 type 22, a current regulating portion 30, and a blank holder 100. [

The bolster 10 supports the entire drawing press including the first die 12.

The first mold 12 is mounted on the bolster 10. The first mold 12 has a space (groove) corresponding to the shape of the lower surface of the product to be processed. FIG. 2 shows an example in which the first die 12 is curved so that the lower surface of the product to be processed has a curved surface. A panel P to be processed into a product is placed on the first mold 12.

The slide 20 is disposed parallel to the bolster 10 so as to face the bolster 10 at a predetermined interval.

The second mold 22 is mounted on the slide 20. The second die 22 has protrusions corresponding to the shape of the upper surface of the product to be processed. The second mold 22 is disposed to face the first mold 12 and the panel P is pressed between the space of the first mold 12 and the protrusion of the second mold 22 to form a product.

The current regulating unit 30 is electrically connected to the coil 110 in the blank holder 100 to induce a magnetic field by flowing current to the coil 110. [ The current regulator 30 changes the magnitude of the magnetic field induced in the coil 110 by adjusting the magnitude of the current, thereby regulating the viscosity of the MR fluid 104.

The blank holder 100 is mounted on the slide 20 away from the second die 22 to press the panel P in contact with the top surface of the first die 12. The blank holder 100 is mounted on the slide 20 in the same manner as the second die 22 and is provided on the edge of the second die 22 with the outer periphery of the slide 20 biased.

The blank holder 100 adjusts the amount of the material (panel) to be molded into the product between the first mold 12 and the second mold 22 by varying the spring force (elastic force, restoring force, etc.). If the inflow amount of the material to be molded is not controlled, wrinkles or breakage may occur in the material.

The blank holder 100 adjusts the pressure output applied in the circumferential direction of the panel P and the tensile force in the longitudinal direction on the side wall of the first mold 12 so that the panel P can be formed into a product without corrugation and breakage .

For this purpose, the blank holder 100 varies the spring force using an MR damper accommodating MR fluid (Magneto-Rheological Fluid).

3 and 4, the blank holder 100 includes a cylinder 102, a MR fluid 104, an outer piston 106, an inner piston 108, a coil 110, and a piston rod 112 . In addition, the blank holder 100 may further include a gas chamber 114 and a floating piston 116.

The cylinder 102 houses the MR fluid 104, the outer piston 106, the inner piston 108, the coil 110, and the like. One end (the right end in Fig. 3) of the cylinder 102 is closed, and the other end (the left end in Fig. 3) is opened and the piston rod 112 penetrates.

MR fluid 104 exhibits isotropic properties due to the free motion of the particles in the absence of a magnetic field, but when the magnetic field is applied, particles induce polarization to form multiple fibrous tissues in the direction of the magnetic field And is an anisotropic material.

The MR fluid (I04) changes its viscosity when an external magnetic field is applied, and its viscosity increases in proportion to the intensity of the applied magnetic field. Since the intensity of the magnetic field is proportional to the magnitude of the current, the spring force of the blank holder 100 can be varied by controlling the intensity of the magnetic field by changing the viscosity of the MR fluid by adjusting the current through the current controller 30 .

In addition, by varying the spring force of the blank holder 100, the pressure output applied in the circumferential direction of the panel P and the tension force in the longitudinal direction of the side wall of the first mold 12 can be adjusted, So that it can be molded into a product.

The outer piston 106 is inserted into the cylinder 102 and performs a linear movement in the cylinder 102. [

The inner piston 108 is provided inside the outer piston 106 and performs a linear movement in the cylinder 102 together with the outer piston 106. [

The coil 110 is provided between the outer piston 106 and the inner piston 108 and receives a current from the current regulator 30 to generate a magnetic field.

3) of the piston rod 112 is engaged with the outer piston 106 and the inner piston 108, and the other end (the left end in FIG. 3) is exposed to the outside of the cylinder 102. 2) is engaged with the slide 20, and the other end (lower end in Fig. 2) is in contact with the upper surface of the panel P, P).

The second mold 22 is pressed against the panel P in a state where the panel P extends across the blank holder 100 between the first mold 12 and the second mold 22 to mold the panel P . By applying the MR damper to the blank holder 100, the spring force of the blank holder can be easily controlled only by the power supply and the current adjustment.

By doing so, the present invention can adjust the blank holding force (BHF) without additional devices in the mold even if the molding conditions are changed, such as changing the material of the material panel, changing the cushion pressure of the drawing press, .

Further, since the MR damper is applied instead of the gas cylinder method in which the gas piping operation is required, or the hydraulic cylinder method in which the hydraulic piping and the hydraulic supply device are to be installed, the blank holding force of the drawing press can be adjusted by power supply alone, Low cost can be realized.

It will be apparent to those skilled in the art that various modifications, substitutions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. will be. Therefore, the embodiments disclosed in the present invention and the accompanying drawings are intended to illustrate and not to limit the technical spirit of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings . The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

10 - Bolster 12 - Type 1
20 - Slide 22 - Type 2
30 - Current regulator 100 - Blank holder
102 - Cylinder 104 - MR fluid
106 - outer piston 108 - inner piston
110 - coil 112 - piston rod

Claims

A first type mounted on a bolster and having a space corresponding to the shape of the lower surface of the product to be processed and supporting a panel to be processed into a product; A second mold mounted on the slide and having a protrusion corresponding to the shape of the top surface of the product to be machined, the mold being arranged to face the first mold; A cylinder which is mounted on the slide and separated from the second mold so as to press the panel contacting the upper surface of the first mold and which contains therein MR fluid (Magneto-Rheological Fluid), an outer piston inserted into the cylinder, A blank holder provided inside the cylinder to perform a linear motion together with the outer piston, a coil provided between the outer piston and the inner piston, and a piston rod having one end coupled to the outer piston and the inner piston; And a current regulator which controls the viscosity of the MR fluid accommodated in the cylinder by controlling the intensity of the magnetic field through the intensity of the current by electrically connecting the coil to the coil to induce a magnetic field in the coil,
The blank holder adjusts the pressure output applied in the circumferential direction of the panel and the tensile force in the longitudinal direction of the first type sidewall so that the panel is formed into a product without wrinkles and breaks. The MR fluid exhibits isotropy when the magnetic field is non- The particles exhibit anisotropy in the magnetic field direction upon application and the viscosity increases in proportion to the intensity of the magnetic field so that the spring force of the blank holder is changed by the viscosity change and the pressure output applied in the circumferential direction of the panel due to the variation of the spring force A drawing press that controls the blank holding force using an MMP damper that adjusts the tensile force in the longitudinal direction on the 1-inch side wall so that the panel is formed into a product without wrinkles and breakage.

delete